Chilled milk-based desserts as emerging probiotic and prebiotic products.

Nowadays, food companies are endeavoring to differentiate their products through creative segmentation and positioning strategies based on superior functionality and quality. Some kinds of dairy desserts have shown a great market potential, as a function of consumers interested in healthier and functional products with fine taste and mouthfeel. In this context, chilled dairy desserts are emerging as attractive options for the incorporation of probiotic cultures and prebiotic ingredients, as seen in the previous launches from the food industry, as well as in the growing number of scientific studies dealing with this subject published in the last years. The main aspects involved in the development of probiotic and/or prebiotic dairy desserts for storage under refrigerated conditions are presented in this review.

Incorporation of soybean by-product okara and inulin in a probiotic soy yoghurt: texture profile and sensory acceptance.

BACKGROUND: This study evaluated the effect of inulin and okara flour on textural and sensory properties of probiotic soy yoghurt (SY) throughout 28 days of storage at 4 °C. Employing a 2(2) design, four formulations of SY produced from soymilk and fermented with an ABT-4 culture (Lactobacillus acidophilus La-5, Bifidobacterium animalis Bb-12 and Streptococcus thermophilus) were studied: SY-C (control); SY-I (with inulin); SY-O (with okara); SY-IO (with inulin + okara). RESULTS: The addition of okara and the refrigerated storage led to significant differences in the instrumental texture parameters of SY (P < 0.05). Inulin and okara did not affect SY sensory acceptability (P > 0.05), but there was a tendency for higher scores in the presence of inulin. On the other hand, the storage period, particularly at 21 days, was unfavourable regarding the acceptance of the different SY. CONCLUSION: The results showed that the addition of okara flour and the storage were significant factors to increase firmness of the soy yoghurts. SY acceptability was not affected by the incorporation of inulin or okara. These results suggest that okara, discarded as industrial waste, may be used in probiotic soy yoghurt, helping to increase the nutritional and functional properties without altering its acceptability.

In vitro modulation of human gut microbiota composition and metabolites by Bifidobacterium longum BB-46 and a citric pectin.

The gut microbiota composition and its metabolites have high impact on human health. Exploitation of prebiotics and probiotics for modulation of gut microbiota can lead to promising outcomes. This study aimed to evaluate the effects of the probiotic strain Bifidobacterium longum BB-46 alone and in combination with a citric pectin from lemon on the gut microbiota from healthy adults using the Simulator of Human Intestinal Microbial Ecosystem (SHIME®). Changes in microbiota composition and in metabolic activity were assessed by the 16S rRNA gene sequencing and by analyses of short-chain fatty acids (SCFAs) and ammonium ions (NH4+). An increase in the relative abundances of Firmicutes (especially the members of Lachnospiraceae and Lactobacillaceae families) and Bacteroidetes was observed during treatment with B. longum BB-46 alone in all compartments of the colon. Treatment with B. longum BB-46 and pectin stimulated an increase in the proportions of genera Faecalibacterium, Eubacterium and Lactobacillus, as well as in the Ruminococcaceae family in the transverse and descending colons. Concurrently, the butyrate levels increased in these two compartments. Additionally, the combination of B. longum BB-46 and pectin reduced the abundance of proteolytic bacteria Bacteroides, Clostridium, Peptoniphilus, and Streptococcus, along with decreased NH4+ production. No significant changes could be observed on NH4+ production by treatment with B. longum BB-46, nor did it increase the amount of SCFAs. In this study, we observed that although each treatment was able to modulate the microbiota, the combination of B. longum BB-46 and pectin was more efficient in decreasing the intestinal NH4+ levels and in increasing butyric acid-producing bacteria. These findings indicate that B. longum BB-46, especially when combined with the specific citric pectin, might have beneficial impact on human health.

Biopreservation by Lactobacillus paracasei in coculture with Streptococcus thermophilus in potentially probiotic and synbiotic fresh cream cheeses.

The viability of Lactobacillus paracasei and its effect on growth of the microbiota in potentially probiotic and synbiotic fresh cheeses during storage at 4 +/- 1 degree C was investigated. Three cheese-making trials (T1, T2, and T3) were prepared in quadruplicate, all supplemented with a Streptococcus thermophilus culture. L. paracasei subsp. paracasei was added to cheeses in T1 and T2, and inulin was added to cheeses in T2. Counts of L. paracasei, S. thermophilus, coliforms, Escherichia coli, Staphylococcus spp., DNase-positive Staphylococcus, and yeasts and molds were monitored during storage for up to 21 days. Viable counts of L. paracasei in probiotic (T1) and synbiotic (T2) cheeses remained above 7 log CFU/g during the entire storage period, whereas counts of S. thermophilus remained above 9.5 log CFU/g for cheeses from TI, T2, and T3. Populations of coliforms, Staphylococcus spp., and DNase-positive Staphylococcus were higher in T3 cheese and differed significantly from those in cheeses from T1 and T2 (P < 0.05). Inhibition of contaminants prevailed when both L. paracasei and S. thermophilus were present in fresh cream cheese and probably was due to acid production by both strains; bacteriocin production was not found. Addition of inulin in T2 did not impact microbial viability (P > 0.05). L. paracasei subsp. paracasei in coculture with S. thermophilus was inhibitory against microbial contaminants in fresh cream cheese with or without the addition of inulin, indicating the potential use of this combination in a probiotic and synbiotic product.

Effect of a probiotic mixed culture on texture profile and sensory performance of Minas fresh cheese in comparison with the traditional products.

The effect of a mixed probiotic culture on instrumental texture, and on sensorial and related properties of Minas fresh cheese during refrigerated storage was investigated. Three cheese-making trials were prepared: T1, with the traditional type O starter culture (Lactococcus lactis subsp. lactis + L. lactis subsp. cremoris), T2 with only lactic acid and T3, with lactic acid and the probiotic ABT culture (Lactobacillus acidophilus La-5 + Bifidobacterium animalis Bb-12 + Streptococcus thermophilus). Instrumental texture profile analysis and related properties were monitored during storage for up to 21 days. Lb. acidophilus and B. animalis were present in high levels throughout storage of cheeses T3, above 6 log cfu.g(-1), threshold required for probiotic activity, and stimulation of the La-5 growth was observed. Cheeses with added probiotic ABT culture, as well as those made adding lactic acid only, showed to be less brittle and with more favorable sensorial features, due to higher pH values. Results indicated that the use of probiotic ABT culture complementary to lactic acid for the purpose of substituting the type O (Lc. lactis subsp. lactis + Lc. lactis subsp. cremoris) culture, traditionally employed for Minas cheese production, is advantageous.

Prebiotic effect of fructooligosaccharide in the simulator of the human intestinal microbial ecosystem (SHIME® model).

Maintaining "gut health" is a goal for scientists throughout the world. Therefore, microbiota management models for testing probiotics, prebiotics, and synbiotics have been developed. The SHIME(®) model was used to study the effect of fructooligosaccharide (FOS) on the fermentation pattern of the colon microbiota. Initially, an inoculum prepared from human feces was introduced into the reactor vessels and stabilized over 2 weeks using a culture medium. This stabilization period was followed by a 2-week control period during which the microbiota was monitored. The microbiota was then subjected to a 4-week treatment period by adding 5 g/day-1 FOS to vessel one (the "stomach" compartment). Plate counts, Denaturing Gradient Gel Electrophoresis (DGGE), short-chain fatty acid (SCFA), and ammonium analyses were used to observe the influence of FOS treatment in simulated colon compartments. A significant increase (P<.01) in the Lactobacillus spp. and Bifidobacterium spp. populations was observed during the treatment period. The DGGE obtained showed the overall microbial community was changed in the ascending colon compartment of the SHIME reactor. FOS induced increase of the SCFA concentration (P<.05) during the treatment period, mainly due to significant increased levels of acetic and butyric acids. However, ammonium concentrations increased during the same period (P<.01). This study indicates the usefulness of in vitro methods that simulate the colon region as part of research towards the improvement of human health.

Effect of galactooligosaccharides and Bifidobacterium animalis Bb-12 on growth of Lactobacillus amylovorus DSM 16698, microbial community structure, and metabolite production in an in vitro colonic model set up with human or pig microbiota.

A validated in vitro model of the large intestine (TIM-2), set up with human or pig faeces, was used to evaluate the impact of potentially probiotic Lactobacillus amylovorus DSM 16698, administered alone (i), in the presence of prebiotic galactooligosaccharides (GOS) (ii), and co-administered with probiotic Bifidobacterium animalis ssp. lactis Bb-12 (Bb-12) (iii) on GOS degradation, microbial growth (L. amylovorus, lactobacilli, bifidobacteria and total bacteria) and metabolite production. High performance anion exchange chromatography revealed that GOS degradation was more pronounced in TIM-2 inoculated with pig faeces than with human faeces. Denaturing gradient gel electrophoresis profiling of PCR-amplified 16S rRNA genes detected a more complex Lactobacillus spp. community in pig faecal material than in human faecal inoculum. According to 16S rRNA gene-targeted qPCR, GOS stimulated the growth of lactobacilli and bifidobacteria in faecal material from both materials. The cumulative production of short chain fatty acids and ammonia was higher (P < 0.05) for pig than for human faeces. However, lactate accumulation was higher (P < 0.05) in the human model and increased after co-administration with GOS and Bb-12. This study reinforced the notion that differences in microbiota composition between target host organisms need to be considered when animal data are extrapolated to human, as is often done with pre- and probiotic intervention studies.

In vitro evaluation of gastrointestinal survival of Lactobacillus amylovorus DSM 16698 alone and combined with galactooligosaccharides, milk and/or Bifidobacterium animalis subsp. lactis Bb-12.

Probiotic properties of Lactobacillus amylovorus DSM 16698 were previously demonstrated in piglets. Here, its potential as a human probiotic was studied in vitro, using the TIM-1 system, which is fully validated to simulate the human upper gastrointestinal tract. To evaluate the effect of the food matrix composition on the survival of L. amylovorus DSM 16698 in TIM-1, the microorganism was inoculated alone or with prebiotic galactooligosaccharides (GOS), partially skimmed milk (PSM) and/or commercial probiotic Bifidobacterium animalis subsp. lactis Bb-12 (Bb-12). Samples were collected from TIM-1 for six hours, at one-hour intervals and L. amylovorus populations were enumerated on MRS agar plates with confirmation of identity of selected isolates by randomly amplified polymorphic DNA (RAPD) fingerprinting. The cumulative survival for L. amylovorus alone (control) was 30% at the end of the experiment (t=6h). Co-administration of L. amylovorus with GOS, PSM and/or Bb-12 increased its survival in comparison with the control significantly from the 4th hour after ingestion onwards (P<0.05). Furthermore, by the use of High Performance Anion Exchange Chromatography, both L. amylovorus and Bb-12 were observed to promptly degrade GOS compounds in samples collected from TIM-1, as assessed at t=2h. Hence, food matrix composition interfered with survival and growth of L. amylovorus during passage through TIM-1, providing leads towards optimization of probiotic properties in vivo.

Viability of Lactobacillus acidophilus in synbiotic guava mousses and its survival under in vitro simulated gastrointestinal conditions.

The effects of refrigeration, freezing and substitution of milk fat by inulin and whey protein concentrate (WPC) on Lactobacillus acidophilus La-5 viability and resistance to gastric and enteric simulated conditions in synbiotic guava mousses effects were investigated. Refrigerated mousses supplemented with WPC presented the best probiotic viability, ranging from 7.77 to 6.24 log cfu/g during 28 days of storage. The highest probiotic populations, above 7.45 log cfu/g, were observed for all frozen mousses during 112 days of storage. Decreased L. acidophilus survival during the in vitro gastrointestinal simulation was observed both for refrigerated and frozen mousses. Nonetheless, for the refrigerated mousses, the addition of inulin enhanced the probiotic survival during the in vitro assays in the first week of storage. L. acidophilus survival in simulated gastrointestinal fluids was also improved through freezing. The frozen storage may be used to provide increased shelf-life for synbiotic guava mousses. Even though the protective effect of inulin and WPC on the probiotic microorganism tested was shown to be more specific for the refrigerated products, the partial replacement of milk fat by these ingredients may also help, as it improves the nutritional value of mousses in both storage conditions.

Functional petit-suisse cheese: measure of the prebiotic effect.

Prebiotics and probiotics are increasingly being used to produce potentially synbiotic foods, particularly through dairy products as vehicles. It is well known that both ingredients may offer benefits to improve the host health. This research aimed to evaluate the prebiotic potential of novel petit-suisse cheeses using an in vitro fermentation model. Five petit-suisse cheese formulations combining candidate prebiotics (inulin, oligofructose, honey) and probiotics (Lactobacillus acidophilus, Bifidobacterium lactis) were tested in vitro using sterile, stirred, batch culture fermentations with human faecal slurry. Measurement of prebiotic effect (MPE) values were generated comparing bacterial changes through determination of maximum growth rates of groups, rate of substrate assimilation and production of lactate and short chain fatty acids. Fastest fermentation and high lactic acid production, promoting increased growth rates of bifidobacteria and lactobacilli, were achieved with addition of prebiotics to a probiotic cheese (made using starter+probiotics). Addition of probiotic strains to control cheese (made using just a starter culture) also resulted in high lactic acid production. Highest MPE values were obtained with addition of prebiotics to a probiotic cheese, followed by addition of prebiotics and/or probiotics to a control cheese. Under the in vitro conditions used, cheese made with the combination of different prebiotics and probiotics resulted in the most promising functional petit-suisse cheese. The study allowed comparison of potentially functional petit-suisse cheeses and screening of preferred synbiotic potential for future market use.

Activity of passion fruit (Passiflora edulis) and guava (Psidium guajava) pulps on Lactobacillus acidophilus in refrigerated mousses / Atividade das polpas de maracujá (Passiflora edulis) e goiaba (Psidium guajava) sobre Lactobacillus acidophilus em musses refrigeradas

Five pilot-scale mousse-making trials were produced and supplemented with Lactobacillus acidophilus La-5 probiotic culture: M1 with passion fruit concentrated juice (PJ); M2 with PJ and prebiotic fibre inulin; M3 with frozen passion fruit pulp (PP); M4 with frozen guava pulp (GP); M5 with GP and lactic acid. The products were stored refrigerated (4°C) and M2 and M5 were also stored frozen (-18°C). Viability of L. acidophilus decreased up to 4.7 log cfu.g-1 in the 21st day for refrigerated mousses containing passion fruit (M1, M2 and M3), whereas the probiotic population remained above 6 log cfu.g-1 in the mousses containing guava (M4 and M5). Inhibition due to acidity was discharged. The addition of fruits to probiotic products should be carefully planned because inhibition of probiotic strains might occur.

Cinco musses foram produzidas em escala piloto e suplementadas com a cultura probiótica de Lactobacillus acidophilus La-5: M1 - com suco concentrado de maracujá (SM); M2 - com SM e fibra prebiótica inulina; M3 - com polpa congelada de maracujá (PM); M4 - com polpa congelada de goiaba (PG); M5 - com PG e ácido lático. Os produtos foram armazenados refrigerados (4°C) e M2 e M5 também congelados (-18°C). A viabilidade de Lactobacillus acidophilus diminuiu em até 4,7 log ufc.g-1 ao 21° dia nas musses contendo maracujá (M1, M3 e M2), enquanto a população do probiótico permaneceu acima de 6 log ufc.g-1 naquelas contendo goiaba (M4 e M5). A inibição devido à acidez foi descartada. A adição de frutas aos produtos probióticos deve ser cuidadosamente planejada, uma vez que pode haver inibição das cepas probióticas.

Effect of a probiotic mixed culture on texture profile and sensory performance of Minas fresh cheese in comparison with the traditional products / Efeito de uma cultura probiótica mista sobre o perfil de textura e o desempenho sensorial de queijo Minas frescal, em comparação aos produtos tradicionais

The effect of a mixed probiotic culture on instrumental texture, and on sensorial and related properties of Minas fresh cheese during refrigerated storage was investigated. Three cheese-making trials were prepared: T1, with the traditional type O starter culture (Lactococcus lactis subsp. lactis + L. lactis subsp. cremoris), T2 with only lactic acid and T3, with lactic acid and the probiotic ABT culture (Lactobacillus acidophilus La-5 + Bifidobacterium animalisBb-12 + Streptococcus thermophilus). Instrumental texture profile analysis and related properties were monitored during storage for up to 21 days. Lb. acidophilus and B. animalis were present in high levels throughout storage of cheeses T3, above 6 log cfu.g-1, threshold required for probiotic activity, and stimulation of the La-5 growth was observed. Cheeses with added probiotic ABT culture, as well as those made adding lactic acid only, showed to be less brittle and with more favorable sensorial features, due to higher pH values. Results indicated that the use of probiotic ABT culture complementary to lactic acid for the purpose of substituting the type O (Lc. lactis subsp. lactis + Lc. lactis subsp. cremoris) culture, traditionally employed for Minas cheese production, is advantageous.

Efeito de uma cultura probiótica mista sobre o perfil de textura e o desempenho sensorial de queijo Minas frescal, em comparação aos produtos tradicionais. O presente trabalho investigou o efeito de uma cultura probiótica mista sobre a textura instrumental, as características sensoriais e as propriedades relacionadas de queijoMinas frescal durante seu armazenamento refrigerado. Três variáveis de elaboração de queijo Minas frescal foram estudadas: T1, empregando-se a cultura lática mesofílica tradicional tipo O (Lactococcus lactis subsp. lactis + L. lactis subsp. cremoris), T2,produzido somente com ácido lático e T3, empregando-se ácido lático e a cultura probiótica ABT (Lactobacillus acidophilus La-5 + Bifidobacterium animalis Bb-12 + Streptococcus thermophilus). O perfil de textura instrumental e as propriedades relacionadas foram monitorados durante 21 dias de armazenamento dos queijos. As populações de Lb. acidophilus e de B. animalis estiveram elevadas durante o armazenamento do queijo T3, acima de 6 log UFC.g-1,população mínima requerida para apresentar efeito probiótico, e foiobservado um estímulo da multiplicação de La-5. Os queijos produzidos com a cultura probiótica ABT, assim como aqueles somente com ácido lático, apresentaram-se menos frágeis e com atributos sensoriais mais favoráveis, devido ao pH mais elevado. Os resultados indicaram ser vantajoso o emprego da cultura probiótica ABT complementarmente ao ácido lático para o propósito de substituição da cultura tipo O (Lc. lactis subsp. lactis + Lc. lactis subsp. cremoris), tradicionalmenteempregada para a produção de queijo Minas frescal.